To stimulate a woman´s clit by rubbing lightly on and around her love button zone. Not to be confused with tweaking, which implies more focused rub-a-dub. Typically you start twiddling and end up tweaking.
See also: no stinky pinky

A few of these words dont even share similar structure as twiddle, though they share similar meaning.
Of course urban dictionary will not show accurate depictions of these words, so assume most of them are similar to just being a little bitch.

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the act of a woman fondling her clitoral appendage with her fingers in a clockwise manner in the privacy of her own home, the campus library bathroom, in the presence of her significant other, or while being taken violently and brilliantly from behind

1 -"You fucking like that?"
-"Oh my God, it feels so good, but do you mind if I twiddle?"

2- "You started masturbating when?"
-"Well, I started humping pillows when I was like 8 or 9, but I don't think I started twiddling until I was 12, when I learned how to download erotic stories"